add a boolean, say for instance "isSnapCouple": true, that will make two connections with this and otherwise compatible automatically connect when close enough. For rolling stock with knuckle connectors and others that are expected to function this way.

But how do you un-couple them? They'd just re-connect.

You got me there actually lets move this to discord

Note: As discussed on discord, the un couple problem mentioned would be fixed like such: they are uncoupled with either a wrench or hitbox, and the coupler will remain disabled until they are clicked/wrenched again

Added in 22.3.0.